(19)
(11) EP 0 204 088 A3

(12) EUROPEAN PATENT APPLICATION

(88) Date of publication A3:
31.08.1988 Bulletin 1988/35

(43) Date of publication A2:
10.12.1986 Bulletin 1986/50

(21) Application number: 86103624

(22) Date of filing: 18.03.1986
(84) Designated Contracting States:
DE FR GB

(30) Priority: 20.03.1985 JP 5463685

(71) Applicants:
  • HITACHI, LTD.
     ()
  • Hitachi Video Engineering Co., Ltd.
     ()

(72) Inventors:
  • Shiomi, Makoto
     ()
  • Miura, Kuniaki
     ()
  • Fukushima, Isao
     ()
  • Moro, Eiji
     ()
  • Kanenari, Shigeaki
     ()

   


(54) Integrated circuit with a phase-locked loop


(57) The IC chip consists of the electronic circuits wherein the voltage control oscillator whose oscillation frequency is dependent on the product of the resistance value of the resister element and the electrostatic capacity of the capacitor element is provided; said capacitor element consists of the first variable capacitor; said voltage control oscillator comprises said capacitor consisting of said first variable capacitor; said first variable capacitor is controlled by the output obtained by detecting the output signal of said voltage control oscillator by its phase, using the predetermined reference signal, whereby the oscillation frequency of said voltage control oscillator can be made to agree with the frequency of said reference signal. Furthermore, the characteristic of said electronic circuit is dependent on the second resister element and the second variable capacitor element; said second variable capacitor is controlled by the output obtained by the phase detection so that dispersions of the resistance value of the resister element and the electrostatic capacity of the capacitor element in said electronic circuit are absorbed automatically.






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